#timplausible: Here's a list of the various weapon properties and what they mean:
Weapon Properties
• 2-handed. Can be held in a single hand, but must be wielded in 2 hands to attack with it.
• Load. Some weapons require extra actions to load before each shot.
• Reach. How close an enemy must be to be affected by this attack. If unspecified, Reach 1.
• Range. Attacks can be made from afar. If any enemy is adjacent to you, your Ranged attacks are made with disadvantage. Add 1 die of disadvantage to gain +2 Range.
• Thrown. Treat a melee weapon as if it had Range. Once thrown, you no longer have it!
• Vicious. Roll 1 additional die whenever you roll crit damage. Remember! Only the Primary Die (the leftmost one) is used for determining whether an attack crits. Every time you roll crit damage, roll the additional Vicious die as well!
As to actions, I'm going to say exchanging weapons would count as a single action. Here's the section form the Quickstart on actions - Defensive actions fall under the category of Heroic Reactions since they occur on your opponents' turn.
I don't see anything offhand about readying an action in either the Quickstart or Core rules - if someone else does, please let me know! - so I'm guessing that they eliminated it in favor of streamlining combat. We could homebrew something pretty easily, but I think for this go around we'll just stick to RAW.